Upsetting part of Prime Time's bit of news (4)
I believe the answer is:
item
'bit of news' is the definition.
(I've seen this before)
'upsetting part of prime time's' is the wordplay.
'upsetting' is a reversal indicator.
'part of' indicates the answer is hidden within the clue.
'meti' is hidden within 'prime times'.
'meti' reversed gives 'ITEM'.
(Other definitions for item that I've seen before include "Time (anag.)" , "Part of a list" , "Also no more" , "Bit of information" , "partners" .)